* {
    margin: 0;
    padding: 0;
}

*{
    box-sizing: border-box;
}

*::before{
    box-sizing: border-box;
}

*::after{
    box-sizing: border-box;
}

#demo{
    word-break: break-all;
}

#div1{
    position: fixed;
    left: 50%;
    transform: rotateX(-50%);
    top: 20px;
}

#div1::before{
    content: "";
    display: block;
    position: absolute;
}

#div1::after{
    content: "";
    display: block;
    position: absolute;
}

@media(max-width:500px){
    #html{
        height: 50vh;
        overflow: auto;
    }

    #div1Wrapper{
        height: 50vh;
    }

    #div1{
        position: relative;
        top: 0;
        right: 0;
    }
}